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transcranial ultrasound

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https://www.readbyqxmd.com/read/28094959/noninvasive-targeted-transcranial-neuromodulation-via-focused-ultrasound-gated-drug-release-from-nanoemulsions
#1
Raag D Airan, Randall A Meyer, Nicholas P K Ellens, Kelly Rhodes, Keyvan Farahani, Martin G Pomper, Shilpa D Kadam, Jordan J Green
Targeted, noninvasive neuromodulation of the brain of an otherwise awake subject could revolutionize both basic and clinical neuroscience. Towards this goal, we have developed nanoparticles that allow noninvasive uncaging of a neuromodulatory drug - in this case the small molecule anesthetic propofol - upon the application of focused ultrasound. These nanoparticles are composed of biodegradable and biocompatible constituents and are activated using sonication parameters that are readily achievable by current clinical transcranial focused ultrasound systems...
January 17, 2017: Nano Letters
https://www.readbyqxmd.com/read/28092531/a-200-1380-khz-quadrifrequency-focused-ultrasound-transducer-for-neurostimulation-in-rodents-and-primates-transcranial-in-vitro-calibration-and-numerical-study-of-the-influence-of-skull-cavity
#2
Charlotte Constans, Thomas Deffieux, Pierre Pouget, Mickael Tanter, Jean-Francois Aubry
Low intensity transcranial focused ultrasound has been demonstrated to produce neuromodulation in both animals and humans. Primarily for technical reasons, frequency is one of the most poorly investigated critical wave parameters. We propose the use of a quadri-band transducer capable of operating at 200, 320, 850 and 1380 kHz for further investigation of the frequency dependence of neuromodulation efficacy while keeping the position of the transducer fixed with respect to the subject's head. This paper presents the results of the transducer calibration in water, in vitro transmission measurements through a monkey skull flap, 3D simulations based on both a μCT-scan of a rat and on CT-scans of 2 macaques...
January 11, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28088127/cerebral-laterality-for-language-is-related-to-adult-salivary-testosterone-levels-but-not-digit-ratio-2d-4d-in-men-a-functional-transcranial-doppler-ultrasound-study
#3
Marietta Papadatou-Pastou, Maryanne Martin
The adequacy of three competing theories of hormonal effects on cerebral laterality are compared using functional transcranial Doppler sonography (fTCD). Thirty-three adult males participated in the study (21 left-handers). Cerebral lateralization was measured by fTCD using an extensively validated word generation task. Adult salivary testosterone (T) and cortisol (C) concentrations were measured by luminescence immunoassay and prenatal T exposure was indirectly estimated by the somatic marker of 2nd to 4th digit length ratio (2D:4D)...
January 11, 2017: Brain and Language
https://www.readbyqxmd.com/read/28069201/pulsed-wave-low-dose-ultrasound-hyperthermia-selectively-enhances-nanodrug-delivery-and-improves-antitumor-efficacy-for-brain-metastasis-of-breast-cancer
#4
Sheng-Kai Wu, Chi-Feng Chiang, Yu-Hone Hsu, Houng-Chi Liou, Wen-Mei Fu, Win-Li Lin
The clinical application of chemotherapeutics for brain tumors remains a challenge due to limitation of blood-brain barrier/blood-tumor barrier (BBB/BTB). In this study, we investigated the effects of low-dose focused ultrasound hyperthermia (UH) on the delivery and therapeutic efficacy of pegylated liposomal doxorubicin (PLD) for brain metastasis of breast cancer. Murine breast cancer cells (4T1-luc2) expressing firefly luciferase were implanted into mouse striatum as a brain tumor model. The mice were intravenously injected with PLD with/without transcranial pulsed-wave/continuous-wave UH (pUH/cUH) treatment on day-6 after tumor implantation...
May 2017: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/28063107/the-relationship-between-right-to-left-shunt-and-brain-white-matter-lesions-in-japanese-patients-with-migraine-a-single-center-study
#5
Akio Iwasaki, Keisuke Suzuki, Hidehiro Takekawa, Ryotaro Takashima, Ayano Suzuki, Shiho Suzuki, Koichi Hirata
BACKGROUND: There may be a link between right-to-left shunt (RLs) and brain white matter lesions (WMLs) in patients with migraine. In this study, we assessed the relationship between WMLs and RLs in Japanese migraine patients. METHODS: A total of 107 consecutive patients with migraine with (MA) and without aura (MWOA) were included in this study. Contrast transcranial Doppler ultrasound was used to detect RLs. WMLs were graded using brain magnetic resonance imaging based on well-established criteria...
December 2017: Journal of Headache and Pain
https://www.readbyqxmd.com/read/28054939/effects-of-resveratrol-on-cognitive-performance-mood-and-cerebrovascular-function-in-post-menopausal-women-a-14-week-randomised-placebo-controlled-intervention-trial
#6
Hamish M Evans, Peter R C Howe, Rachel H X Wong
We tested whether chronic supplementation with resveratrol (a phytoestrogen) could improve cerebrovascular function, cognition and mood in post-menopausal women. Eighty post-menopausal women aged 45-85 years were randomised to take trans-resveratrol or placebo for 14 weeks and the effects on cognitive performance, cerebral blood flow velocity and pulsatility index (a measure of arterial stiffness) in the middle cerebral artery (using transcranial Doppler ultrasound), and cerebrovascular responsiveness (CVR) to both cognitive testing and hypercapnia were assessed...
January 3, 2017: Nutrients
https://www.readbyqxmd.com/read/28017126/recent-advances-in-transcranial-focused-ultrasound-fus-triggered-brain-delivery
#7
Nidhi Nainwal
Successful delivery of therapeutic agents in the brain is very challenging, which makes treatment of various brain disorders very difficult. One of the major causes of this difficulty is the presence of physiological barriers in the brain like blood brain barrier (BBB) and blood cerebro-spinal fluid (CSF) barrier. These barriers are very specific and restrict the entry of water soluble agents and ionized molecule. Only lipid soluble and small molecular size agents are allowed to enter into the brain. But there are several serious brain diseases in which the use of only conventional small molecular mass lipophilic drug is not effective...
December 22, 2016: Current Drug Targets
https://www.readbyqxmd.com/read/28005566/anesthesia-for-functional-endoscopic-sinus-surgery
#8
Daniel A Carlton, Satish Govindaraj
PURPOSE OF REVIEW: The present article summarizes anesthetic techniques used during functional endoscopic sinus surgery to decrease bleeding and aid in creating a clear surgical field. The applicable physiology behind these anesthetic techniques is reviewed with emphasis on the effect on bleeding and the surgical field. Deliberate hypotension, reverse Trendelenburg positioning, regional anesthesia, and cerebral monitoring are discussed. RECENT FINDINGS: There are mixed data as to whether traditional inhalation anesthesia or total intravenous anesthesia is superior with respect to better surgical fields and decreased blood loss...
February 2017: Current Opinion in Otolaryngology & Head and Neck Surgery
https://www.readbyqxmd.com/read/28004334/noninvasive-neuromonitoring-current-utility-in-subarachnoid-hemorrhage-traumatic-brain-injury-and-stroke
#9
Luisa Vinciguerra, Julian Bösel
Noninvasive neuromonitoring is increasingly being used to monitor the course of primary brain injury and limit secondary brain damage of patients in the neurocritical care unit. Proposed advantages over invasive neuromonitoring methods include a lower risk of infection and bleeding, no need for surgical installation, mobility and portability of some devices, and safety. The question, however, is whether noninvasive neuromonitoring is practical and trustworthy enough already. We searched the recent literature and reviewed English-language studies on noninvasive neuromonitoring in subarachnoid hemorrhage, traumatic brain injury, and ischemic and hemorrhagic stroke between the years 2010 and 2015...
December 21, 2016: Neurocritical Care
https://www.readbyqxmd.com/read/28000971/safety-and-tolerability-of-sonovue%C3%A2-in-patients-with-large-artery-anterior-circulation-acute-stroke
#10
Claudio Baracchini, Federica Viaro, Silvia Favaretto, Anna Palmieri, Caterina Kulyk, Francesco Causin, Filippo Farina, Enzo Ballotta
BACKGROUND AND PURPOSE: Ultrasound contrast agents (UCAs) are routinely used to improve the visualization of intracranial arteries. Since a higher rate of intracranial hemorrhage (ICH) has been observed in patients undergoing sonothrombolysis in combination with UCAs, we conducted this study with the aim of assessing safety and tolerability of SonoVue® in patients with acute ischemic stroke due to anterior circulation large artery occlusion (LAO) and eligible to intravenous thrombolysis and/or mechanical thrombectomy...
December 21, 2016: Journal of Neuroimaging: Official Journal of the American Society of Neuroimaging
https://www.readbyqxmd.com/read/27935138/characteristics-of-accredited-transcranial-doppler-ultrasound-laboratories-in-the-united-states
#11
Mary Beth Farrell, John Y Choi, Endrit Ziu, Kevin M Cockroft
PURPOSE: The aim of this study was to describe in detail the characteristics and accreditation compliance of laboratories in the United States applying for Intersocietal Accreditation Commission (IAC) transcranial Doppler (TCD) accreditation. METHODS: This was a retrospective study of all applicant laboratories from 2012 to 2015. We used the IAC database to extract laboratory characteristics and guideline compliance metrics. RESULTS: Evaluation of 97 laboratories demonstrated that 67% were hospital-based and located in the South (43...
December 9, 2016: Journal of Neuroimaging: Official Journal of the American Society of Neuroimaging
https://www.readbyqxmd.com/read/27881556/nitrite-and-s-nitrosohemoglobin-exchange-across-the-human-cerebral-and-femoral-circulation-relationship-to-basal-and-exercise-blood-flow-responses-to-hypoxia
#12
Damian M Bailey, Peter Rasmussen, Morten Overgaard, Kevin A Evans, Aske M Bohm, Thomas Seifert, Patrice Brassard, Morten Zaar, Henning B Nielsen, Peter Raven, Niels H Secher
BACKGROUND: -The mechanisms underlying red blood cell (RBC)-mediated hypoxic vasodilation remain controversial with separate roles for nitrite (NO2(-)) and S-nitrosohemoglobin (SNO-Hb) widely contested given their ability to transduce nitric oxide (NO) bioactivity within the microcirculation. To establish their relative contribution in vivo, we quantified arterial-venous (a-v) concentration gradients across the human cerebral and femoral circulation at rest and during exercise, an ideal model system characterized by physiological extremes of O2 tension and blood flow...
November 15, 2016: Circulation
https://www.readbyqxmd.com/read/27875362/relationship-between-hiv-infection-antiretroviral-therapy-inflammatory-markers-and-cerebrovascular-endothelial-function-among-adults-in-urban-china
#13
Felicia C Chow, Yanling Li, Yinghuan Hu, Joy Chan, Huanling Wang, Weihai Xu, Richard W Price, Farzaneh A Sorond, Taisheng Li
BACKGROUND: Cerebrovascular risk is increased in people living with HIV infection compared with age-matched uninfected individuals. Cerebrovascular endothelial dysfunction related to antiretroviral therapy and inflammation may contribute to higher stroke risk in HIV infection. METHODS: We compared cerebral vasoreactivity-a measure of cerebrovascular endothelial function assessed by the breath holding index (BHI) using transcranial Doppler ultrasound-between virologically suppressed Chinese HIV-infected individuals followed in an HIV clinic in Beijing, China and uninfected controls...
November 21, 2016: Journal of Acquired Immune Deficiency Syndromes: JAIDS
https://www.readbyqxmd.com/read/27845920/a-multi-frequency-sparse-hemispherical-ultrasound-phased-array-for-microbubble-mediated-transcranial-therapy-and-simultaneous-cavitation-mapping
#14
Lulu Deng, Meaghan A O'Reilly, Ryan M Jones, Ran An, Kullervo Hynynen
Focused ultrasound (FUS) phased arrays show promise for non-invasive brain therapy. However, the majority of them are limited to a single transmit/receive frequency and therefore lack the versatility to expose and monitor the treatment volume. Multi-frequency arrays could offer variable transmit focal sizes under a fixed aperture, and detect different spectral content on receive for imaging purposes. Here, a three-frequency (306, 612, and 1224 kHz) sparse hemispherical ultrasound phased array (31.8 cm aperture; 128 transducer modules) was constructed and evaluated for microbubble-mediated transcranial therapy and simultaneous cavitation mapping...
December 21, 2016: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/27843693/treatment-and-imaging-of-intracranial-atherosclerotic-stenosis-current-perspectives-and-future-directions
#15
REVIEW
Ido R van den Wijngaard, Ghislaine Holswilder, Marianne A A van Walderveen, Ale Algra, Marieke J H Wermer, Osama O Zaidat, Jelis Boiten
BACKGROUND AND PURPOSE: Intracranial atherosclerosis is a common cause of stroke worldwide. It results in ischemic stroke due to different mechanisms including artery-to-artery embolism, in situ thrombo-occlusion, occlusion of perforating arteries, and hemodynamic failure. In this review, we present an overview of current treatment and imaging modalities in intracranial atherosclerotic stenosis. METHODS: PubMed was searched for relevant articles in English that evaluated the treatment and imaging of intracranial atherosclerotic stenosis (ICAS)...
November 2016: Brain and Behavior
https://www.readbyqxmd.com/read/27837190/hyperoxia-results-in-increased-aerobic-metabolism-following-acute-brain-injury
#16
Arnab Ghosh, David Highton, Christina Kolyva, Ilias Tachtsidis, Clare E Elwell, Martin Smith
Acute brain injury is associated with depressed aerobic metabolism. Below a critical mitochondrial pO2 cytochrome c oxidase, the terminal electron acceptor in the mitochondrial respiratory chain, fails to sustain oxidative phosphorylation. After acute brain injury, this ischaemic threshold might be shifted into apparently normal levels of tissue oxygenation. We investigated the oxygen dependency of aerobic metabolism in 16 acutely brain-injured patients using a 120-min normobaric hyperoxia challenge in the acute phase (24-72 h) post-injury and multimodal neuromonitoring, including transcranial Doppler ultrasound-measured cerebral blood flow velocity, cerebral microdialysis-derived lactate-pyruvate ratio (LPR), brain tissue pO2 (pbrO2), and tissue oxygenation index and cytochrome c oxidase oxidation state (oxCCO) measured using broadband spectroscopy...
November 11, 2016: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/27796172/risk-factors-between-intracranial-extracranial-atherosclerosis-and-anterior-posterior-circulation-stroke-in-ischaemic-stroke
#17
Yan Li, Yefeng Cai, Min Zhao, Jingbo Sun
OBJECTIVES: Atherosclerosis is an important cause of stroke and remains a challenge for stroke prevention. Risk factors involved in atherosclerotic stroke and anterior and posterior circulation strokes (ACS and PCS, respectively) are different. The purpose of this study is to investigate differences in risk factors between intracranial and extracranial atherosclerosis (ICAS and ECAS), ACS and PCS, and ICAS/ECAS with ACS/PCS in a Chinese acute ischaemic stroke population. METHODS: We analysed 551 ischaemic stroke patients who had been enrolled between August 2005 and July 2008...
January 2017: Neurological Research
https://www.readbyqxmd.com/read/27786169/therapeutic-potential-of-transcranial-focused-ultrasound-for-rett-syndrome
#18
Shih-Jen Tsai
Rett syndrome (RTT) is a severe neurodevelopmental disorder occurring almost exclusively in females and is caused by loss-of-function mutations in the gene encoding methyl-CpG-binding protein 2 (MeCP2) in the majority of cases. MeCP2 is essential for the normal function of nerve cells, including neuronal development, maturation, and synaptic activity. RTT is characterized by normal early development followed by autistic-like features, slowed brain and head growth, gait abnormalities, seizures, breathing irregularities, and cognitive disabilities...
October 27, 2016: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
https://www.readbyqxmd.com/read/27784293/simultaneous-acoustic-stimulation-of-human-primary-and-secondary-somatosensory-cortices-using-transcranial-focused-ultrasound
#19
Wonhye Lee, Yong An Chung, Yujin Jung, In-Uk Song, Seung-Schik Yoo
BACKGROUND: Transcranial focused ultrasound (FUS) is gaining momentum as a novel non-invasive brain stimulation method, with promising potential for superior spatial resolution and depth penetration compared to transcranial magnetic stimulation or transcranial direct current stimulation. We examined the presence of tactile sensations elicited by FUS stimulation of two separate brain regions in humans-the primary (SI) and secondary (SII) somatosensory areas of the hand, as guided by individual-specific functional magnetic resonance imaging data...
October 26, 2016: BMC Neuroscience
https://www.readbyqxmd.com/read/27779134/a-numerical-study-on-the-oblique-focus-in-mr-guided-transcranial-focused-ultrasound
#20
Alec Hughes, Yuexi Huang, Aki Pulkkinen, Michael L Schwartz, Andres M Lozano, Kullervo Hynynen
Recent clinical data showing thermal lesions from treatments of essential tremor using MR-guided transcranial focused ultrasound shows that in many cases the focus is oblique to the main axis of the phased array. The potential for this obliquity to extend the focus into lateral regions of the brain has led to speculation as to the cause of the oblique focus, and whether it is possible to realign the focus. Numerical simulations were performed on clinical export data to analyze the causes of the oblique focus and determine methods for its correction...
November 21, 2016: Physics in Medicine and Biology
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